Hey guys, ive got this big aluminium evaporator from a E46 BMW, My waterblock is copper though, and i know the whole galvanic corrosion stuff. So i was wondering by having this big rad will outweigh having to add loads of corrosion blocker and **** like that. heres the rad

Correct me if I'm wrong, but does that only have the single tube passing through the fins? If so, our computer loops don't put out near enough heat for that to work effectively. It's also hard to see the size of this as we don't have a reference point.

I still don't think it'll work very well for a computer loop. The beauty of our radiators, is their tubing runs throughout the radiator, not just a couple points. The thing you posted is essentially a large heatsink attached to the pipes. Our temperatures are not high enough, nor is there enough tubing surface area for that to work properly in a computer loop.

The picture isn't doing justice for this thing. I understand what an evaporator is, however based on the picture and your slight description, I'm not seeing how it'll work.

Does the tube zig-zag through the fins or behind it?
Are the only connecting points of the fins to the tube, just what you can see at the top of the picture?
Do each of the larger connecting pieces also hold the liquid or are they solid aluminum? If that's the case, the flow will not be good throughout the radiator.